The invention relates to removing heat from integrated circuit devices mounted on a support structure.
Integrated circuit devices, such as microprocessors, DRAMs, and ASICs may contain millions of transistors. These integrated circuit devices, which may be bare dies mounted directly on a support structure (e.g., printed wiring boards or ceramic boards) or encapsulated in plastic packages, generate large amounts of heat during operation. Heat increases a device's electrical resistance which slows down the device and may affect the device's overall performance. Heat also accelerates wear and tear on the device and may reduce a device's overall life expectancy. Metal can also cause corrosion of metal liners used in the integrated circuit. Therefore, it is desirable to remove heat from integrated circuit devices and generally keep them as cool as possible during operation.
Integrated circuit devices are also very moisture sensitive. Extended exposure to humidity from the air may allow moisture to seep into the devices and damage them. For example, moisture seeping underneath the protective overcoat (PO) of an integrated circuit device will cause the PO to delaminate. Therefore, it is desirable to encapsulate integrated circuit devices in hermetically sealed packages to protect them from moisture. The packages also protect integrated circuit devices from damage due to physical stress during assembly and testing.